作者：
周美华徐静波Won-jei CHOEnvironmental Science and Engineering College
Donghua University Shanghai 200051 College of Electronic and Electrical Engineering
Shanghai University of Science and Technology Shanghai 200336 Department of Polymer Science and Engineering
Pusan National University Pusan 609-735 South Koreaour oil absorbents based on styrene butadiene (SBR) i.e. pure SBR (PS) 4. tert-butylstyrene-SBR (PBS) EPDM-SBR network (PES) and 4.tert-butylstyrene-EPDMSBR (PBES) were produced from crosslinking polymerization of uncured styrene butadiene rubber (SBR) 4-tert-butylstyrene (tBS) and ethylene-propylenc-diene terpolymer (EPDM). The reaction took place in toluene using benzoyl peroxide (BPO) as an initiator. Uncured SBR was used as both a pre-polymer and a crosslink agent in this work and the crosslinked polymer was identified by IR spectroscopy. The oil absorbency of the crosslinked polymer was evaluated with the method ASTM (F726-81). The order of maximum oil absorbency was PBES>PBS>PES>PS. The maximum values of oil absorbency of PBES and PBS were 74.0g/g and 69.5g/g respectively. Gel fractions and swelling kinetic constants however had the opposite sequences. The swelling kinetic constant of PS evaluated by an experimental equation was 49. 97×10~(-2)h~(-1).
Four oil absorbents based on styrene butadiene (SBR), i.e., pure SBR (PS), 4. tert-butylstyrene-SBR (PBS), EPDM-SBR network (PES) and ***-butylstyrene-EPDMSBR (PBES), were produced from crosslinking polymerization of ...
详细信息
Four oil absorbents based on styrene butadiene (SBR), i.e., pure SBR (PS), 4. tert-butylstyrene-SBR (PBS), EPDM-SBR network (PES) and ***-butylstyrene-EPDMSBR (PBES), were produced from crosslinking polymerization of uncured styrene butadiene rubber (SBR), 4-tert-butylstyrene (tBS) and ethylene-propylenc-diene terpolymer (EPDM). The reaction took place in toluene using benzoyl peroxide (BPO) as an initiator. Uncured SBR was used as both a pre-polymer and a crosslink agent in this work, and the crosslinked polymer was identified by IR spectroscopy. The oil absorbency of the crosslinked polymer was evaluated with the method ASTM (F726-81). The order of maximum oil absorbency was PBES>PBS>PES>PS. The maximum values of oil absorbency of PBES and PBS were 74.0g/g and 69.5g/g, respectively. Gel fractions and swelling kinetic constants, however, had the opposite sequences. The swelling kinetic constant of PS evaluated by an experimental equation was 49. 97×10^(-2)h^(-1).
We proposed an approach to precisely control the density of tethered chains on solid substrates using PEO-b-PS and PLLA-b-PS. As the crystallization temperature Tx increased, the PEO or PLLA lamellar crystal thickness...
详细信息
We proposed an approach to precisely control the density of tethered chains on solid substrates using PEO-b-PS and PLLA-b-PS. As the crystallization temperature Tx increased, the PEO or PLLA lamellar crystal thickness dL increased as well as the reduced tethering density σ˜ of the PS chains. The onset of tethered PS chains overcrowding in solution occurs at σ˜*∼3.7–3.8 as evidenced by an abrupt change in the slope between (dL)−1 and Tx. This results from the extra surface free energy created by the tethered chain that starts to affect the growth barrier of the crystalline blocks.
Interfacial activities of the cowpea mosaic virus (CPMV) between two immiscible liquids are examined by fluorescent labeling. The cover picture shows a ribbon diagram of CPMV, fluorescence laser scanning confocal micr...
详细信息
Interfacial activities of the cowpea mosaic virus (CPMV) between two immiscible liquids are examined by fluorescent labeling. The cover picture shows a ribbon diagram of CPMV, fluorescence laser scanning confocal microscopy images of perfluorodecalin droplets in water encapsulated by a layer of CPMV, and the structure of a CPMV particle labeled with a fluorescent dye and biotin. In their Communication on page 2420 ff., T. P. Russell, Q. Wang, and co-workers describe the formation of robust membranes by the self-assembly of CPMV bionanoparticles at liquid–liquid interfaces.
We have performed the molecular dynamics (MD) simulations of polymer crystallization from a stretched amorphous state, employing a linear poly(ethylene) molecular model. During the simulation, the crystal domain emerg...
We have performed the molecular dynamics (MD) simulations of polymer crystallization from a stretched amorphous state, employing a linear poly(ethylene) molecular model. During the simulation, the crystal domain emerged and grew in the amorphous state, whereas the shape of the whole polymer chain remained effectively unchanged. The MD simulation suggests the ordering initiates from the segments with a spatial scale smaller than the stem length, and from many places in a chain. In this study, the change in the molecular motion of subchain during crystallization and its dependence on the size of the subchain are examined.
暂无评论